Author: jeffgillman003

Lungs and Plants

As a third grader I distinctly remember my teacher telling our class about how it was bad to smoke because the smoke would make your lungs filthy.  She used her aunt as an example.  It seems that this aunt was a heavy smoker.  One day this aunt was eating popcorn and accidently inhaled a piece.  About 6 months or so after she inhaled it she coughed it up and it looked like a little piece of tar.  Funny how some stories stay with you.

The interesting thing to me is that my third grade teacher’s aunt isn’t the only one who has inhaled a seed, and that the inhilation of the seed needen’t mean curtains for the plant.  Recently a gentleman inhaled a pea (or bean, the exact type of plant still appears to be a bit up in the air — ) which sprouted in his lung http://pagingdrgupta.blogs.cnn.com/2010/08/13/plant-sprouts-in-mans-lung/?iref=NS1http://pagingdrgupta.blogs.cnn.com/2010/08/13/plant-sprouts-in-mans-lung/?iref=NS1 and last year there was a gentleman from Russia who apparently had a fir growing in his lung (though it seems more likely that the man actually inhaled the tip of a more mature tree — too much vodka? — My question is whether there were roots, and if so, does that make this a novel way to root a fir cutting?) http://www.dailymail.co.uk/news/worldnews/article-1169861/Shocked-Russian-surgeons-open-man-thought-tumour–FIR-TREE-inside-lung.html

After doing a quick search I also found a case where a child had a germinating seed of an apple in his lung, a case where a germinating bean caused a young girls right lung to collapse. And, apparently, both children and adults inhale grass seeds now and again though I couldn’t find much information on how frequently these seeds actually germinate in the lungs.

I wonder, is this the beginning of an interesting coevolution between plants and people?  Could a plant evolve so that the seeds were inhaled by humans, grew in our lungs, and then, later were expelled to be inhaled by other humans?  Just a random thought on a slow Thursday.

Balanced Fertilizer and Peak Phosphorus

When I first started reading extension recommendations for plants around 15 years ago now, I read a lot about “balanced fertilizers”.  Today I still see balanced fertilizers recommended, but not nearly as frequently, which is a good thing.

At this point you may be asking yourself “what is a balanced fertilizer?”  A balanced fertilizer is one that has three numbers on its label which are the same — such as a 10-10-10 or a 14-14-14 (Nitrogen, Phosphorus and Potassium are the three nutrients indicated by
these numbers).  Although it might seem like equal numbers would mean equal amounts of these nutrients, these numbers actually indicate percent Nitrogen, percent P expressed as P2O5 (in other words, if you took all of the phosphorus present in the fertilizer, made it into P2O5 and then added it back to the fertilizer and figured out what percent of the fertilizer that made up — that would be the second number) and percent potassium expressed as K2O (basically the same as the phosphorus example you saw previously).

But here’s the problem.  The amount of phosphorus, and often potassium, that is added when you use a balanced fertilizer is typically out of line with the amount that the plant needs.  This is because fertilizers are usually applied based on the amount of nitrogen that a plant needs.  The reason that a balanced fertilizer was usually recommended was that phosphorus and potassium levels in these fertilizers is high enough that they provide all of those elements that a plant needed without being toxic to the plant.  The problem is that, while the levels of these nutrients added might not be toxic, they are in excess of what is usually needed.

OK, so we’re adding excess phosphorus and potassium, what’s the problem?  Well, for the potassium the problem isn’t usually that big a deal.  In fact, a fertilizer bag with the first and third numbers equal may be what’s called for in many cases — fruits and nuts in particular often like a higher level of potassium.  Additionally, the world has a pretty big store of potassium so we’re not likely to run out any time soon.  Phosphorus, on the other hand, is a little bit different.

Phosphorus is a bit more hard to find in large quantity than either of the other elements in a bag of fertilizer.  Because of this it is often the element that limits the growth of plants, for example algae.  When phosphorus runs off into a lake or other body of water it can allow algae to go crazy and use up all of the oxygen in the water killing fish and other creatures (actually it’s the dead algae that do this — bacteria use oxygen while breaking the algae down).  Most of you are familiar with this and know that it’s the reason why Minnesota and now Wisconsin have banned the use of phosphorus fertilizers on lawns without a soil test.

But here’s what you may not know.  Most of the phosphorus which we use for fertilizers comes from rock phosphate.  Rock phosphate is mined in only a few places around the world, Florida being one.  Just as it is a foregone conclusion that we will run out of oil someday, it is also a foregone, but lesser known, conclusion that we will run out of rock phosphate.  Estimates are that we will reach “Peak Phosphorus” (in other words maximum phosphorus production.) in 20 years or so and that we will run out in 50 – 100 years.  Here’s an interesting article on the situation  http://www.foreignpolicy.com/articles/2010/04/20/peak_phosphorus

So conserve our natural resources and skip the balanced fertilizer.  When asked for a general use fertilizer recommendation I usually recommend something with a ratio of roughly 5-1-2, with a higher potassium content if you’re growing fruits or nuts.

Almost But Not Quite

Today I was reading an interesting gardening website with a wide variety of advice, some good and some not so good.  As I analyzed the website in my mind to figure out why some stuff was good and some stuff was bad it occurred to me that the problem was that a lot of the stuff that the author was recommending was based on testimonials.  And then it occurred to me that many of you out there might not know what a testimonial is and why recommendations based on testimonials shouldn’t be recommended — and then viola! I had a blog post.

A testimonial is testimony presented by one person about their experiences with something.  It’s like when a friend tells you that dryer lint controls slugs in a flowerbed. Don’t laugh, this is a real suggestion on one website!  This person decided that it was appropriate to put dryer lint around their garden, and when they did, slug damage appeared to be reduced.  Good for them.  But is it good for you?  The answer is maybe.

The problem is that this person is missing the two things that we need when assessing whether a particular thing works.  First, we need a a control, and second, we need replication.  Let’s use the dryer lint example.
We have no idea whether, if we hadn’t put out the dryer lint, the slug population might not have dwindled anyway.  To find out whether it might have we need to treat only a portion of our garden with dryer lint and then see if the treated portion has more or less damage than the untreated portion after a few weeks.  The untreated part of the garden is called a control and it is necessary for a good experiment.  But it isn’t the only thing necessary for a good experiment, so is replication.

It is possible that the part of the garden which was treated with the lint had less slug damage than the control portion of the garden for some reason besides the lint — for example, perhaps the area where the lint was applied happened to be further from the sprinker than the other section — and slugs like it moist.   So to combat possible problems like this you need to conduct your experiment more than once.  In other words, you need to replicate your trials.  This might be done by doing this experiment over multiple years, by having other people in your gardening club try it too, or by dividing up sections in your garden into six or so equally sized sections so that three randomly selected sections get treated with lint and three don’t.  Or, best of all, do all of these things — multiple years, multiple gardens, and multiple plots within a garden!  If we did more testing like that I have a funny feeling that we’d have fewer crappy products for sale.

Testimonials are interesting, but don’t get fooled into thinking that they prove anything.  They don’t.  You need control and replication to demonstate that something really works.

Jicama (The Yam Bean)

Every once in awhile I get the urge to try and find something interesting in old literature, and today was one of those days.  So I went over to my pile of old “Journal of Economic Entomology” journals and snatched a 1943 issue from the top.  The pest issues that we had to deal with during the war years were interesting because resources were tight — we had DDT (and lead arsenate), but all of it was going to the front to protect our soldiers from lice.  So scientists back home were trying new things.  One which I had never heard of before today was getting a serious look: The yam bean.  The yam bean is a tropical legume which has a great deal of potential as a high nutrient food crop (the root of the bean is what is edible, not the seeds).  The food part is interesting to me, but more interesting is the fact that a dust could be made from grinding the beans into a powder which would kill insects.  After looking through some articles I discovered that the primary source of toxicity in the yam bean is rotenone and some similar chemicals.  I’m not a big fan of rotenone, still, this plant is fascinating.  An edible root and seeds which can be used very effectively as an insecticide.  Why wasn’t this plant more common 50 or 100 years ago?  What other plants are we missing out there which are useful?

Want an organic source of nitrogen that isn’t shipped from halfway across the world? Urine luck

There are lots of organic fertilizers out there:  Fish emulsions, corn gluten meal, guano.  Many of these fertilizers (all that I listed above with the exception of the guano) are by-products of some other industry.  Still, they need to be shipped from somewhere to somewhere to get to our garden and so they cost energy — and of course they cost us money.  But there is a high nitrogen fertilizer that you can use which doesn’t come from a long way away, and that’s pee.  Holly  mentioned using pee to help compost piles of stray a few months ago (you can find the news story on the right side of this blog), and I, for one, think it’s a great idea.  But really, pee can be used as a fertilizer without the compost.

Yesterday I was working on a project and decided to goof off a little by figuring out how much nitrogen was actually in urine.  Here’s the conclusion — Urine contains about 4,000 pats per million nitrogen.  In terms of what plants can handle, that’s a lot (which is why dogs produce “dog spots” when they pee on a small area of ground — too much nitrogen in a small area).  400 parts per million nitrogen, applied once a week in irrigation water, is what you might apply to encourage the growth of greenhouse plants.  Urine, by the way, is also relatively sterile (unless you’re dealing with a bladder infection) and so using urine is relatively safe as long as it’s used quickly.  It also conserves water because you don’t need to flush.  So, the way I figure it, you could mix 1 part urine with 9 parts water and have a really good once a week (or two weeks) fertilizer application for your flowers (I don’t know if I could bring myself to fertilize cabbage, broccoli, or tomatoes with it…).  You’d be saving yourself the cost of fertilizer, saving the environmental cost of shipping the fertilizer you might otherwise purchase, saving water, and you’d have something unique to tell your gardening friends about.  Win – win situation as far as I’m concerned.

A quiz – from our visiting professor

We’re glad to have Dr. Rohwer back for another visit!  Here’s his Friday quiz – see if you can figure out what happened to his tomatoes.

"Exhibit A is a tomato in our garden. We had 2 tomatoes last year a couple feet away from this one, they met the same fate. Wilting at about flowering time, and water did not resolve the wilting. Previous to last year, the area was turfgrass for who knows how long. There was no vascular discoloration or oozing."

Charlie also included more evidence: "Exhibit B – arrow points to former location of the wilted tomato behind the garlic and carrots, amongst young beets, onions, kohlrabi, and bolting radishes and spinach. Exhibit C – arrow shows the former location of the tomato.  In the far background you can see our roof. We have 2 rain barrels collecting most roof runoff." This water is used in their vegetable garden.

 
And here’s a bit of diagnostic information: "Plants sensitive to this condition exhibit symptoms such as chlorosis (foliar yellowing), wilting, and eventual death."

Can you figure out what happened? Answer on Monday!

Propagating in the air

Most gardeners that I know have tried to produce roots on stem cuttings from plants that they like.  Sometimes this turns out well for them, particularly if they are working with what we call an easy-to-root species, and sometimes it turns out poorly.  OK, in all honesty, it often turns out poorly.  The problem is that plants like very particular conditions when they’re growing roots and the typical gardener is going to have a tough time providing these conditions.  So here’s an option.  There is a method of propagation called air-layering which works on many plants that stem cuttings won’t work on and which doesn’t need all of the specialized equipment either.  It’s not a sure-fire technique, but it’s more likely that the average gardener will get this technique to work than any other (with the exception of seeds).

Here’s how it works.  Select a small branch from the plant you want to propagate.  Find a point on the branch about 6 to 12 inches from its apex and then cut out a ring of bark around the circumference of the tree.  This will allow water and nutrients to flow into the branch (assuming you didn’t cut too deep), but it won’t allow the carbohydrates produced in the branch to flow down the stem — instead they’ll be stuck where you made your cut and be used by the plant to produce new roots.

Around the cut you may apply a rooting hormone.  This will help the root production to some degree.  To keep the wound moist apply a heaping helping of moist peat and keep it in place with plastic wrap — or a cut up sandwich bag.  Wire ties, elastic bands or string will hold these in place.  Now you just sit back and wait.

It usually takes anywhere from 4-8 weeks for roots to emerge (you’ll see them when they do because they’ll push up against the plastic wrap).  Once the roots are there plant your new tree/shrub/perennial in it’s own container just like you would any new plant, care for it as you would any other plant, and then plant it out if you so choose (I like to keep young plants like this in a container for at least a few months — the landscape is usually a harsher environment than a container, and so the time in the container gives it a chance to get stronger and store needed nutrient reserves.)

Visiting Virginia

The first thing that I did, gardening wise, when I moved to Minnesota from Georgia was to try all of the plants that I had grown to love in the South in the North — hoping beyond hope that perhaps someone had made a mistake when listing the hardiness zones of these plants.  The result was a mess of dead lacebark elms, Japanese maples, and butterfly bushes.  One plant that I did find could live, albeit just barely, was the beautyberry — a purple fruiting shrub that would survive as a perennial in Minnesota, just barely getting up to my knee — just enough to tease me.

Today I’m giving a few talks in Blacksburg VA and visiting fellow GP Holly Scoggins.  She runs the Hahn gardens here and has some truly beautiful specimens of many plants that I covet, beautyberry among them.  I am so jealous of people who live in the South and can grow this stuff to its full potential!

In this photo I share a beer with a large, lush beautyberry.  I think it might have been more impressed by a higher caliber beer.